A5 TDI Intake Manifold Fault Causing Power Loss & Jerks

Had similar symptoms on my A4 2.0 TDI from 2013. The intake manifold flap actuator was indeed the culprit. The engine light came on after about a week of experiencing reduced power and rough running. The air intake system showed clear signs of carbon buildup, which caused the manifold flap to stick. The airflow control mechanism was completely seized, preventing proper engine breathing. This meant the engine control unit could not regulate the airflow correctly, leading to those acceleration jerks and power loss you described. This turned out to be a serious issue requiring immediate attention. Left unchecked, it can cause further engine damage and increased fuel consumption. The repair involved replacing the complete intake manifold assembly along with cleaning the air intake system. The hissing sound you mention is typical of a failed manifold flap, its exactly what my car was doing. The symptoms match perfectly with what I experienced, particularly the rough running and power loss during acceleration. Worth noting that after the repair, engine performance returned to normal immediately. The engine light cleared and fuel economy improved significantly. Getting this fixed quickly is important to prevent additional engine stress.

Thanks for sharing your experience. This is super helpful as I am dealing with the exact same engine misfire symptoms on my A5 right now. The manifold flap issue appears to be quite common then. I am planning to get it checked next week as the reduced power is getting worse. Do you remember roughly how much you paid for the complete repair? Also curious if you have had any recurring airflow control problems since getting it fixed?

Just got the repair done last week actually, the problematic flap control mechanism in the intake system was completely replaced. Total cost came to 465 Euro for fixing the defective intake manifold switch, which was exactly what the issue turned out to be. The engine light disappeared right after the repair and everything is running smoothly now. The air intake system is working perfectly, no more hissing sounds or power loss during acceleration. The engine response is crisp again and fuel consumption has returned to normal levels. Have not experienced any recurring airflow control problems since the fix. The mechanic mentioned this is a known issue with these engines, but once properly repaired with new parts, it typically stays resolved. The key is addressing it promptly when the symptoms first appear to prevent additional engine stress. Your decision to get it checked next week is smart, better to fix the intake manifold flap control early before it potentially causes more extensive engine damage. Based on my experience, you should notice an immediate improvement once repaired.

I took it to the mechanic last week after reading your replies. The diagnosis confirmed what we suspected, a faulty manifold flap causing the engine misfire issues. The airflow control system was completely compromised, just as you described. The repair cost came to 520 Euro, slightly more than yours but still reasonable considering the work involved. They replaced the entire intake manifold assembly and cleaned out the system. The hissing noise disappeared immediately and the engine runs perfectly now. Really glad I got it sorted quickly, the mechanic showed me the old parts and the flap control mechanism was completely seized. Engine performance is back to normal and fuel economy has improved significantly. No more jerky acceleration or power loss issues. The whole repair took about 4 hours and I can definitely recommend getting it fixed right away if anyone else experiences similar symptoms. Thanks again for helping identify the problem, saved me from potentially more expensive repairs down the line.